Spring powered key mechanism



Jan. 16, 1962 E. E. REYNOLDS SPRING POWERED KEY MECHANISM Original Fileu Aug. 23, 1957 2 Sheets-Sheet 1 OOOOOOOOOOOOOOOOOO OCOOOOOOOOOOOOOOOO OOOOOOOOO Jan. 16, 1962 E. E. REYNOLDS 3,017,039

SPRING POWERED KEY MECHANISM Original Filed Aug. 23, 1957 2 Sheets-Sheet 2 United States Patent Smith-Corona Marchant, Inc., a corporation of New York Original application Aug. 23, 1957, Ser. No. 679,909.

Divided and this application Nov. 17, 1958, Ser. No. 774,502

4 Claims. (Cl. 235-145) The invention relates to office machines and more particularly to improvements in key structures used in such machines.

This application is a division of copending application Serial No. 679,909 of Eugene E. Reynolds and William E. Thomas, filed on August 23, 1957, for Calculating Machines.

It is an object of the invention to enable an improved spring-powered mechanism for depressing a key, such enabling being in response to light manual depression of the key.

It is a further object to enable an improved springpowered key depressing mechanism, and to subsequently enable a spring-powered key return mechanism.

' It is a further object to enable an improved springpowered key depressing mechanism, to subsequently disable said mechanism, and then automatically enable a spring-powered key return mechanism.

It is a further object to enable a key depressing spring upon light manual depression of the key and permit a spring to restore said key following the operation of a disabling means for the depressing spring.

FIGURE 1 is a top view of a calculating machine in which the invention is embodied.

FIGURE 2 is a right side View of the control key unlatching and recocking mechanism in an initial position.

FIGURE 3 is a right side view of the mechanism in FIGURE 2, the control key being shown in depressed position.

The depression of the decimal key 230 (FIG. 1) performs several conditioning and operating functions which differ in accordance with whether an add-subtract conditioning key 306 or a multiply-divide conditioning key 307 stands depressed when the decimal key 230 is depressed. During multiplying and dividing operations, the depression of the decimal key initiates four distinct functions, and during adding and subtracting operations it initiates six distinct functions. The nature of these functions are explained in detail in the parent application to which reference is made since an understanding of these functions is not necessary to an understanding of the present invention.

The force which must be exerted to depress this key is abnormal and therefore an assisting means is provided which is under constant spring tension and may be enabled to pull down the decimal key. The spring assisting means is enabled during the initial portion of a manual depression of the decimal key 2130 (FIG. 2).

The key is fixed to a transverse bail 572. which is supported at either end by a pair of arms. One arm of said pair is an arm 5177 (FIG. 2). Arm 577 is mounted for limited rocking movement on a shaft 578. The arm 577 has an extension 5 79, and a spring 580 connected between extension 579 and a lever 581. Spring 580 normally holds the decimal key in the raised position shown in FIGURE 2. Lever 581 is held in the raised position shown by a latch 582 which is pivoted on a shaft 583 fixed in the framework of the machine. A strong spring 58 4 continually urges lever 581 in a clockwise direction.

Depression of the decimal key 230 and the integral bail 57 2 first causes an ear 572a on the bail to rock latch 582 clockwise against the tension of a spring 582a thereby releasing an ear 585 on lever 581 Upon release, lever 581 is moved in a clockwise direction by the spring 584. A hook 586, pivotally mounted on the lever 581 at 5 88 overlies an ear 58-7 on arm 5 77 and therefore, the arms, bail 5'72. and the decimal key 230 are pulled down with lever 581 to provide the power for initiating the various functions.

A hand crank 363 (FIG. 1) provides the power for the performance of the various operations or functions in the machine and is fully described in the parent application. The hand crank may be moved in either direction and the restoring of the lever and key will occur as hereinafter explained regardless of the direction the hand crank is moved.

The decimal key is raised to its initial position by spring means which are released under the control of the wide cam 544 (FIGS. 2 and 3) which is rotated once for each rotation of the handcrank 3 33. A cam follower 701 (FIGS. 2 and 3) is pivotally mounted at 70 2 and carries a roller 703 which follows the earn 544. A pin 704, carried by the follower 701 underlies an arm 705 of a lever 706. The lever 706 is pivoted on the framework of the machine at 707. Upon rotation of cam 544 in either direction, follower 701 rocks in a clockwise direction and pin 704 rocks lever 706 in a counterclockwise direction. At such time an ear 708 on the lever 706 normally moves in an are below an extension 709 of hook 586. It will be recalled, however, that upon depression of the decimal key 230, the strong spring 584 is enabled to pull lever 5 81 in a clockwise direction, and through hook 586, holds the arm 577 in depressed position, as shown in FIGURE 3. In the depressed position of the parts, extension 70 9 stands in the path of movement of ear 708 on lever 706, and therefore ear 708 contacts and moves lever 709 and the integral hook 586 in a counterclockwise direction about the pivot shaft 588' on lever 581. This disconnects hook 58-6 from car 587 on the arm 577 and the spring 580 is free to return arm 577 to the initial position. In this manner, the decimal key is returned by spring power to its initial position in the early part of a handcrank even through the auxiliary member or lever 5 81 is retained in the lower position by spring 584. It is to be noted that the configuration of casm 544 determines the exact cyclic point at which the kev is released to return to the initial position.

In the last portion of the cycle of rotation of cam 544, the pin 704 on bellcrank 701 engages the edge 58 1a of the lever 581 and returns the same to the initial position shown in FIGURE 2, thus re-establishing the latched connection between the hook 586 and the arm 577, and also re-establishing the connection between latch 5'82 and the lever 581.

From the foregoing, it will be clear that the spring means 584 pulls the decimal key to the fully depressed position and the spring means 580 returns the decimal key to the initial position.

The invention claimed is:

1. In a light touch key mechanism having a heavily loaded control key lever, the combination of two springs for, respectively, moving the key lever to a fully depressed position and returning the key lever to the initial position, comprising: a heavily loaded auxiliary member spring urged by the first of said springs to depressed position, a detent normally enabled to maintain the auxiliary member in raised position against the tension of said first spring, a releasable connecting means between the auxiliary member and the key lever, means operable upon an initial depression of the key lever to disable the detent and permit the first spring to move the auxiliary member, the connecting means and the key lever to the fully depressed position, a releasing lever, and a restoring lever cyclically operable to actuate the releasing lever to move the connecting means to a release position during the initial portion of a restoring cycle to permit the second spring to return the key lever to the initial position, said restoring lever being cyclically operable to restore said auxiliary member to the initial position during a predetermined later portion of said cycle.

2. In a light touch key mechanism having a heavily loaded control key lever, and means responsive to depression thereof for initiating the operation of a respective mechanism, the combination of: a first spring yieldably urging the key leverto raised position, a heavily loaded auxiliary member, a releasable connecting device between the auxiliarly member and the control key lever, a second spring yieldably urging the auxiliary member from an initial position to a depressed position, a normally enabled detent holding the auxiliary member in raised position, means responsive to the initial portion of depression of the key lever to disable the detent to permit the spring-urged auxiliary member to depress the key lever and hold it in depressed position, releasing means for disconnecting the connecting device from the key lever to permit the key lever to rise under the urging of the first spring, and a restoring lever cyclically operable first to actuate the releasing means to disconnect the device and second to return the auxiliary member to the initial position to reconnect the device to the key lever and re-enable the detent to maintain the auxiliary member in raised position.

3. In a light touch key mechanism having a heavily loaded control key lever and means responsive to depression thereof for initiating the operation of a respective mechanism, the combination of: a heavily loaded auxiliary member, a first spring connected between the control key lever and the auxiliary member to maintain a predetermined tension on said first spring in the initial position of the key lever, a releasable connecting device between the auxiliary member and the control key lever, a second spring yieldably urging the auxiliary member from an initial position to a depressed position, a normally enabled detent holding the auxiliary member in raised position, means responsive to the initial portion of depression of the key lever to disable the detent to permit the spring-urged auxiliary member to depress the key lever and hold it in depressed position with the same predetermined tension maintained on said first spring as maintained in the initial position of the key lever, releasing means for disconnecting the connecting device from the key lever to permit release of tension in said first spring to raise the key lever to the initial position, and a restoring lever cyclically operable first to actuate the releasing means to disconnect the device and second to return the auxiliary member to the initial position to restore said predetermined tension to said first spring, to reconnect the device to the key lever, and to re-enable the detent to maintain the auxiliary member in raised position.

4. In a light touch key mechanism, the combination of: a heavily loaded control key lever, means for urging the key lever to a first position, a heavily loaded second lever, a releasable device connecting the second lever to the key lever, means connected to said second lever for urging the second lever from a first to a second position, a latch operable to hold the second lever in the first position, means operable upon an initial movement of the key lever to move the latch and release the second lever and key lever for movement to respective second positions, a restoring lever operable during theinitial portion of a restoring cycle to move the releasable device to break said connection and permit the key lever to return to the first position, said restoring lever being cyclically operable to move the second lever to the first position for re-engagement with said latch and to permit the releasable device to be reconnected during a predetermined later portion of said cycle.

References Cited in the file of this patent UNITED STATES PATENTS 1,525,311 Martin Feb. 3, 1925 1,528,018 Hamann Mar. 3, 1925 2,393,018 Boyden Jan. 15, 1946 1 2,552,789 Hopkins May 15, 1951 2,678,162 Hutton May 11, 1954 

